rowan

RAID0 stripes the data in pieces over two or more drives, so you will definitely need all drives present in order to copy off your data. In addition, RAID is often proprietary to each manufacturer (or even down to model level) so even if you were able to hook them up to another motherboard which has RAID support and enough free ports it may not actually recognise the array.

If you want a quick fix then buy a cheap power supply to copy off your data, then stick it on the back of the shelf for the next occasion you need a spare PSU.

Now, couple more things...

...are you sure it's just the PSU that's dead?...

...What about backups?... (What are they? :D )